Abstract
Abstract The Class 0 protostar IRAS 16293-2422 Source A is known to be a binary system (A1 and A2) or even a multiple system that processes a complex outflow structure. We have observed this source in the C34S, SO, and OCS lines at 3.1 mm with the Atacama Large Millimeter/submillimeter Array. A substructure of this source is traced by our high angular-resolution observation (0.″12; 20 au) of the continuum emission. The northwest–southeast (NW–SE) outflow on a 2″ scale is detected in the SO (J N = 22–11) line. Based on the morphology of the SO distribution, this bipolar outflow structure seems to originate from the protostar A1 and its circumstellar disk, or the circummultiple structure of Source A. The rotation motion of the NW–SE outflow is detected in the SO and OCS emissions. We evaluate the specific angular momentum of the outflowing gas to be (8.6–14.3) × 10−4 km s−1 pc. If the driving source of this outflow is the protostar A1 and its circumstellar disk, it can be a potential mechanism to extract the specific angular momentum of the disk structure. These results can be a hint for the outflow launching mechanism in this source. Furthermore, they provide us with an important clue to resolve the complicated structure of IRAS 16293-2422 Source A.
Highlights
In the last decade, the study of disk-formation around solar-type protostars has made extensive progress both theoretically and observationally
Since a large fraction of stars are born as a member of a multiple or binary system (e.g. Chen et al 2013; Duchêne & Kraus 2013; Tobin et al 2016), investigating jet and outflow structures of binary/multiple systems is essential for the star-formation processes ongoing there
It can be regarded to trace the circummultiple disk/envelope system of IRAS 16293–2422 Source A, whose mid-plane is reported to extend along the position angle (P.A.) of 50◦ (OY20)
Summary
The study of disk-formation around solar-type protostars has made extensive progress both theoretically and observationally. In the disk-formation process around a newly-born protostar, outflows/jets and disks are mutually related via the angular momentum. Their relation has not been elucidated in detail by observations. There is still difficulty to judge where outflows/jets are launched from; a central protostellar object, an inner-edge of a disk, or a disk surface. The outflow launching process in multiple systems is expected to be complex. Since a large fraction of stars are born as a member of a multiple or binary system Chen et al.2013; Duchêne & Kraus 2013; Tobin et al 2016), investigating jet and outflow structures of binary/multiple systems is essential for the star-formation processes ongoing there Since a large fraction of stars are born as a member of a multiple or binary system (e.g. Chen et al.2013; Duchêne & Kraus 2013; Tobin et al 2016), investigating jet and outflow structures of binary/multiple systems is essential for the star-formation processes ongoing there
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